Question

Two Carnot engines work in series between the source and sink temperatures of 550 K and 350 K. If both engines develop equal power determine the intermediate temperature.

Answer 1

hows the arrangement of the system. 

Temperature of the source, T₁ = 550 K 

Temperature of the sink, T₃ = 350 K 

Intermediate temperature, T₂ : 

The efficiencies of the engines HE₁ and HE₂ are given by

Now from eqns. (iii) and (iv), we get 

T₁ – T₂ = T₂ – T₃ 

2T₂ = T₁ + T₃ = 550 + 350 

∴ T₂ = 450 K 

Hence intermediate temperature = 450 K.